Radiation Poisoning

"Radiation isn't something I ever expected to see in the world of Aventyr, as they did not possess the ability to conceive of it. Their magic was too tempting to navigate technologies to look for the atom. However, there are ways of traveling to worlds beyond this one where the extinction of magic allowed for the invention of Atomic Weapons. Unscrupulous travelers took this knowledge back with them and unleashed it in the most terrifying way. However, the element of magic warped the resulting radiation into the stuff of undeath. Victims rose in droves, threatening a zombie apocalypse. Still, mages from Droheim have been known to collect the stuff in hopes of enhancing their necromancies even further." - from the annals of time.